Louis van Gaal admits the "very impressive" Ryan Giggs must decide his own managerial future after insisting that he cannot influence the identity of his successor at Manchester United.

Giggs has spent the last 18 months working as Van Gaal's assistant at Old Trafford, having spent a season as play­er-coach under David Moyes following the retirement of Alex Ferguson at the end of the 2012-13 campaign.

The 42-year-old had been expected to succeed Van Gaal as United manager at the end of the Dutchman's contract next year, but the Welshman has received no guarantees from the Old Trafford hier­archy.

And with Giggs understood to be keen to move into management, Van Gaal admits that the decision on where to take his first steps is solely down to Giggs.

"Now I cannot say he should be my successor any more because I don't want to reign beyond my grave. I have stopped that message. In my first year, it was good to say it, though."

Having groomed the likes of Jose Mourinho and Ronald Koeman in the early stages of their coaching careers, Van Gaal has helped influence the rise of some of the leading managers in the game. He says that Giggs has impressed him hugely with his grasp of his role at United and commitment to learning the job.

"I am impressed by his hard-work­ing attitude because ex-players are not often good examples of hard-working managers," Van Gaal says.

"He is very hard-working and it is impressive. What he has to do for me is analyse the oppo­nent and his explanation of that is very good.

"His coaching capacity, his reading of the game, are excellent and he can say the right things to my players. I am very happy with him."